Abstract: This disclosure describes a user equipment device (UE). The UE includes one or more antennas; one or more radios, where each of the radios is configured to perform cellular communication using a plurality of radio access technologies (RATs) that support voice over an Internet protocol (IP) multimedia subsystem (IMS); one or more processors coupled to the one or more radios, where the one or more processors are configured to cause the UE to perform operations including: sending, via a first RAT, a first request for IMS registration to an IMS server; receiving, from the IMS server, an IMS rejection message indicating failure of the IMS registration; determining, based on the IMS rejection message, that the IMS registration failure is temporary; responsively re-attempting IMS registration with the IMS server; and determining to camp on the first RAT in response to receiving an IMS acceptance message from the IMS server.

Abstract: User equipment devices (UEs) and methods are described for performing single network slice selection assistance information (S-NSSAI)-aware public land mobile network (PLMN) selection in a roaming scenario. A mapping list is received that includes a mapping of a plurality of public land mobile networks (PLMNs) to corresponding S-NSSAI values. The mapping list is received from a home PLMN (HPLMN) of the UE over non-3rd generation partnership (non-3GPP) access, from a server, or from a Universal Mobile Telecommunications Service (UMTS) subscriber identity module (USIM) of the UE. An available PLMN is determined that is mapped to a preferred S-NSSAI value of the UE based on the mapping list. A connection is established with the available PLMN.

Abstract: Embodiments are presented herein of apparatuses, systems, and methods for mitigation of secondary cell failures. A user equipment (UE) may establish communication with a macro cellular base station. The UE may perform a signal quality measurement of a small cell base station and compare the signal quality measurement to a threshold. Based on the signal quality measurement exceeding the threshold, the UE may attempt to additionally connect to the small cell base station. In response to a radio link failure of the second base station, the UE may modify the first threshold. In response to subsequent failures to additionally connect to the small cell base station using the modified first threshold, the UE may disable connections to the small cell base station.

Abstract: Systems and methods provide steering of roaming (SoR) information during a user equipment (UE) mobility registration process. In other systems and methods, instead of triggering mobility and periodic registration, a UE performs initial registration until a valid SoR is received in a visited country or network as long as a subscriber identification module (SIM) or a universal SIM (USIM) of the UE indicates that the UE is expected to receive SoR information due to initial registration in a visited public land mobile network (VPLMN).

Abstract: A user equipment (UE) is configured to prioritize a plurality of Public Land Mobile Networks (PLMNs) from an aggregate roaming priority public land mobile network (RPPLMN) list containing the plurality of PLMNs into a plurality of prioritized PLMNs and connect to a selected PLMN from the plurality of prioritized PLMNs based on a priority of the selected PLMN. The UE is further configured to determine if an application processor (AP) assisted location service is available, wherein the AP-assisted service is configured to identify a plurality of deployed PLMNs and a plurality of frequencies used by the plurality of deployed PLMNs at a current geographical location of the UE and when the AP) assisted location service is available, determining if a registered PLMN (RPLMN) is valid in a current mobile country code (MCC).

Abstract: This disclosure describes a communication system associated with a radio access technology (RAT). The communication system includes an Internet protocol (IP) multimedia subsystem (IMS) server, and one or more processors configured to perform operations. The operations include receiving, from a user equipment device (UE) camped on the RAT, a request for IMS Packet Data Unit (PDU) establishment or IMS session initiation protocol (SIP) registration; sending to the UE a rejection message associated with the SIP registration or the IMS PDU establishment; receiving, from the UE, an IMS failure message that comprises an IMS failure cause; determining, based on the IMS failure message, whether the IMS failure cause is temporary or permanent; and responsive to determining that the IMS failure is temporary, temporarily disabling the RAT for the UE.

Abstract: Apparatuses, systems, and methods for SoR list management and PLMN selection based on an SoR list. A UE may receive an SoR container which may include a list of OPLMNs. The UE may store a prior list of OPLMNs stored on a USIM of the UE on a memory of the UE. The UE replace the prior list of OPLMNs stored on the USIM with the list of OPLMNs included in the SoR container. The UE may consider the prior list of OPLMNs as a lower priority list as compared to the list of OPLMNs stored on the USIM. Additionally, in response to determining to move from a current PLMN, the UE may scan for a new PLMN based on the list of OPLMNs stored on the USIM.

Abstract: Apparatuses, systems, and methods for SoR list management and PLMN selection based on an SoR list. A UE may receive an SoR container which may include a list of OPLMNs. The UE may store a prior list of OPLMNs stored on a USIM of the UE on a memory of the UE. The UE replace the prior list of OPLMNs stored on the USIM with the list of OPLMNs included in the SoR container. The UE may consider the prior list of OPLMNs as a lower priority list as compared to the list of OPLMNs stored on the USIM. Additionally, in response to determining to move from a current PLMN, the UE may scan for a new PLMN based on the list of OPLMNs stored on the USIM.

Abstract: This disclosure describes a user equipment device (UE). The UE includes one or more antennas; one or more radios, where each of the radios is configured to perform cellular communication using a plurality of radio access technologies (RATs) that support voice over an Internet protocol (IP) multimedia subsystem (IMS); one or more processors coupled to the one or more radios, where the one or more processors are configured to cause the UE to perform operations including: sending, via a first RAT, a first request for IMS registration to an IMS server; receiving, from the IMS server, an IMS rejection message indicating failure of the IMS registration; determining, based on the IMS rejection message, that the IMS registration failure is temporary; responsively re-attempting IMS registration with the IMS server; and determining to camp on the first RAT in response to receiving an IMS acceptance message from the IMS server.

Abstract: This disclosure describes a user equipment device (UE). The UE includes one or more antennas; one or more radios configured to perform cellular communication using a plurality of radio access technologies (RATs) that support voice over an Internet protocol (IP) multimedia subsystem (IMS); and one or more processors coupled to the one or more radios. The one or more processors are configured to cause the UE to perform operations including: sending, to a communications network associated with a first RAT of the plurality of RATs, a first request for IMS registration, wherein the UE is camped on a first cell of the first RAT; determining, based on an IMS rejection failure, that the IMS registration failure is due to a temporary radio failure; and responsively attempting to perform the IMS registration on at least one other cell of the first RAT.

Abstract: This disclosure describes a communication system associated with a radio access technology (RAT). The communication system includes an Internet protocol (IP) multimedia subsystem (IMS) server, and one or more processors configured to perform operations. The operations include receiving, from a user equipment device (UE) camped on the RAT, a request for IMS Packet Data Unit (PDU) establishment or IMS session initiation protocol (SIP) registration; sending to the UE a rejection message associated with the SIP registration or the IMS PDU establishment; receiving, from the UE, an IMS failure message that comprises an IMS failure cause; determining, based on the IMS failure message, whether the IMS failure cause is temporary or permanent; and responsive to determining that the IMS failure is temporary, temporarily disabling the RAT for the UE.

Abstract: Embodiments are presented herein of apparatuses, systems, and methods for mitigation of secondary cell failures. A user equipment (UE) may establish communication with a macro cellular base station. The UE may perform a signal quality measurement of a small cell base station and compare the signal quality measurement to a threshold. Based on the signal quality measurement exceeding the threshold, the UE may attempt to additionally connect to the small cell base station. In response to a radio link failure of the second base station, the UE may modify the first threshold. In response to subsequent failures to additionally connect to the small cell base station using the modified first threshold, the UE may disable connections to the small cell base station.

Abstract: Embodiments are presented herein of apparatuses, systems, and methods for mitigation of secondary cell failures. A user equipment (UE) may establish communication with a macro cellular base station. The UE may perform a signal quality measurement of a small cell base station and compare the signal quality measurement to a threshold. Based on the signal quality measurement exceeding the threshold, the UE may attempt to additionally connect to the small cell base station. In response to a radio link failure of the second base station, the UE may modify the first threshold. In response to subsequent failures to additionally connect to the small cell base station using the modified first threshold, the UE may disable connections to the small cell base station.

Abstract: Systems and methods provide steering of roaming (SoR) information during a user equipment (UE) mobility registration process. In other systems and methods, instead of triggering mobility and periodic registration, a UE performs initial registration until a valid SoR is received in a visited country or network as long as a subscriber identification module (SIM) or a universal SIM (USIM) of the UE indicates that the UE is expected to receive SoR information due to initial registration in a visited public land mobile network (VPLMN).

Abstract: Embodiments are presented herein of apparatuses, systems, and methods for mitigation of secondary cell failures. A user equipment (UE) may establish communication with a macro cellular base station. The UE may perform a signal quality measurement of a small cell base station and compare the signal quality measurement to a threshold. Based on the signal quality measurement exceeding the threshold, the UE may attempt to additionally connect to the small cell base station. In response to a radio link failure of the second base station, the UE may modify the first threshold. In response to subsequent failures to additionally connect to the small cell base station using the modified first threshold, the UE may disable connections to the small cell base station.

Abstract: Apparatuses, systems, and methods for SoR list management and PLMN selection based on an SoR list. A UE may receive an SoR container which may include a list of OPLMNs. The UE may store a prior list of OPLMNs stored on a USIM of the UE on a memory of the UE. The UE replace the prior list of OPLMNs stored on the USIM with the list of OPLMNs included in the SoR container. The UE may consider the prior list of OPLMNs as a lower priority list as compared to the list of OPLMNs stored on the USIM. Additionally, in response to determining to move from a current PLMN, the UE may scan for a new PLMN based on the list of OPLMNs stored on the USIM.

Abstract: A user equipment (UE) is configured to prioritize a plurality of Public Land Mobile Networks (PLMNs) from an aggregate roaming priority public land mobile network (RPPLMN) list containing the plurality of PLMNs into a plurality of prioritized PLMNs and connect to a selected PLMN from the plurality of prioritized PLMNs based on a priority of the selected PLMN. The UE is further configured to determine if an application processor (AP) assisted location service is available, wherein the AP-assisted service is configured to identify a plurality of deployed PLMNs and a plurality of frequencies used by the plurality of deployed PLMNs at a current geographical location of the UE and when the AP) assisted location service is available, determining if a registered PLMN (RPLMN) is valid in a current mobile country code (MCC).

Abstract: Methods and apparatuses are disclosed for requesting and providing service of a network slice deemed essential by a user equipment (UE). The UE transmits a request message to the network indicating that essential services are requested, and identifying the essential network slice. Based on the information in the request message, the serving network communicates with one or more network nodes to determine whether the requested services can be provided. This information is packaged in a response message and transmitted to the UE. If the current network is capable of servicing the requested network slice, then the UE remains with the current network. If not, then the UE initiates a search for an alternative network (PLMN or SNPN) capable of supporting the requested services. A successful search causes the UE to register with the newly-found network, whereas an unsuccessful search causes the UE to re-register with the current network.

Abstract: User equipment devices (UEs) and methods are described for performing single network slice selection assistance information (S-NSSAI)-aware public land mobile network (PLMN) selection in a roaming scenario. A mapping list is received that includes a mapping of a plurality of public land mobile networks (PLMNs) to corresponding S-NSSAI values. The mapping list is received from a home PLMN (HPLMN) of the UE over non-3rd generation partnership (non-3GPP) access, from a server, or from a Universal Mobile Telecommunications Service (UMTS) subscriber identity module (USIM) of the UE. An available PLMN is determined that is mapped to a preferred S-NSSAI value of the UE based on the mapping list. A connection is established with the available PLMN.

Abstract: Methods, systems and apparatus for a user equipment to mitigate interference in a wireless charging state. The user equipment may determine when the user equipment enters a wireless charging state and, when the user equipment enters the wireless charging state, activate an interference mitigation. The user equipment may further determine when the UE exits the wireless charging state and, when the user equipment exits the wireless charging state, deactivate the interference mitigation.